Indicating systems



Jan, 29, 1957 R. M. PAGE INDICATING SYSTEMS Filed May 7, 1942 PUL SEGEA/ERA TOR 7. PULSE nited States Patent INDICATING SYSTEMS Robert M.Page, Washington, D. C.

Application May 7, 1942, Serial No. 442,097 1s claims. (ci. 343-11)(Granted under Title 35, U. S. 'Code (1952), sec. 266) This inventionrelates to indicating systems and more particularly to methods and meansfor facilitating the interpretation of indications produced by radioecho ranging devices or similar apparatuses.

Certain radio echo ranging apparatuses include means for detecting thepresence `of all remote objects included within a iield extending 360about the apparatus, means for determining the range and direction ofthe detected objects with respect to the apparatus, and suitableindicating means, such as a cathode ray oscillograph, for providing avisual plan representation of the area eXtending 360 about thevapparatus upon which indications of the detected remote objects are`produced in such a manner to simultaneously show range and directionthereof.

More particularly, the foregoing types of Vradio echo ranging apparatusinclude a directional beam antenna supplied with a source of energy forproducing a highly directional beam of energy. The antenna is continual-1y rotated in order to scan an area 360 about the apparatus with suchdirectional energy whereby the energy is reected from all objectsincluded within the scanned area. Such apparatuses further include meansfor producing a radial sweep on the cathode ray oscillograph whichrotates in synchronism with rotation of the directional beam antenna sothat the radial sweep at all times radially propagates in a directionwhich corresponds to the direction of the source of energy emitted fromthe antenna. Means are also provided for receiving reflections of theenergy from remote objects and for modulating the intensity of the sweepline on the oscillograph whenever reected energy is received. By propersynchronization of the rate of emission of the directive energy with therate of propagation of the radial sweep, the positions of reflectedenergy indications on the sweep -lines are a direct measurement of rangeof remote lobjects while the angular position of the sweep line at `theinstant indications vappear thereon Vrepresents the direction of remoteobjects. In operation of an apparatus of `the above type, the intensityof the radial sweep ismodulated so that only reflected energyindications, which Vappear as small arcs, the length of which varieswith the range, are only visible on the oscillograph screen. With anindication of the foregoing type it becomes extremely difficult toaccurately determine the -range and direction of remote objects sinceVreference indications of range and direction are not provided.

It is therefore an object of the present invention to provide novelmethods and .means Afor facilitating -the interpretation of indications,produced by certain radio echo ranging devices or similar apparatuses.Y

Another object is toprovide a radio-echo ranging apparatus having novel`indicating means whereby range and direction of 'remote -objects arequickly obtained with a high degree of accuracy.

Another object is to provide Aa novel 'device for ,producing radial'Calibrating `lines cn'the screen of the 'oscillograph associated withradio echo ranging apparatus for rice . facilitating the determinationof direction of detected objects.

Still another object of the invention is to provide a novel device forproducing a series of concentric calibrating circles on the oscillographscreen which correspond to various ranges about the apparatus.

Other objects and features of the invention will appear more fully fromthe following detailed description when considered in connection withthe accompanying drawing which discloses several embodiments of theinvention. It is to be expressly understood, however, that the drawingis designed for purposes of illustration only and not as a definition ofthe limits of the invention, reference for the latter purpose being hadto the appended claims.

In the drawing, wherein similar reference characters denote similarparts throughout the several views:

Fig. l is a diagrammatic showing of a radio echo ranging device whichVproduces simultaneous indication of range and direction of remoteobjects;

Fig. 2 illustrates a device for producing radial calibrating marks onthe viewing screen of the oscillograph disclosed in Fig. l; Y

Fig. 3 shows application ofthe radial Calibrating marks on the screen ofthe oscillograph;

Fig. 4 is .a diagrammatic showing of a device for producing a pluralityof concentric circular Calibrating marks on the viewing screen of .theoscillograph disclosed in Fig. l;

Fig. 5 is an illustration employed for describing operation of thedevice disclosed in Fig. 4, and

Pig. 6 illustrates the application of concentric circular caiibratingmarks on the viewing screen of the oscillograph.

With reference more particularly to Fig. l, a radio echo ranging`apparatus is disclosed therein `including a rotatable directional beamantenna li), a cathode ray oscillograph 11, radio frequency pulsetransmitter 12 and a radio frequency pulse receiver 13. Transmitter 12and receiver i3 are connected to antenna 10 through duplexing circuit14. The duplexing circuit automatically functions toV form an individualconnection between transmitter 12 and antenna Y10 and between theantenna and receiver 13 so that a single antenna may be employed fortransmission as well as reception. A duplexing circuit constructed inaccordance with the principles disclosed in the application of Leo C.Young and Robert M. Page for Impedance Coupling and Decoupling System,Serial No. 326,640, led March 29, 1.940, now Patent No. 2,688,746,datedSeptember 7, 1954, adequately serves this purpose. Antenna 10 maytake the form of any directional beam antenna capable of producing 4ahighly directive beam of energy, while transmitter 12 and rece'iver 13are constructed in such ,a manner to properly transmit and receive radiopulses, the types Vof transmitters and receivers employed inconventional television systems are suitable for these purposes.Operation of transmitter 12 is controlled `by electronic keyer 15 insuch a manner that equally spaced radio pulses are emitted therefrom Vata predetermined rate. Dscillograph 11 is provided'with electromagneticdeliection coils '16 mounted `on anti-friction bearings for rotationabout the oscil'lograph. Deflection coils 16 are wound in such a mannerto produce varying magnetic lines of force within the -oscillo'graph,when saw-tooth varying current is applied thereto, with a `source ofdirectly current, `for Adeecting the beam offelectrons generated withinlthe oscillograph in a radial direction from the center of theoscillograph, upon application of each saw-tooth Wave form. .SuchVvdeflection of the electron beam produces a radial sweeper trace Ia Ionviewing screen 17 of oscillograph 11. lB19/,proper adjustment of biasAsupply 18 the intensity of the electron beam is normally modulated so 3that the radial sweep a is not visible. generator 19 is provided forapplying saw-tooth wave forms as well as a source of direct current todeilection coils 16 through suitable slip rings. Synchronizer 20 isemployed with connections to electronic keyer and saw-tooth wavegenerator 19, in order to properly synchronize the pulses emitted fromtransmitter 12 with the application of saw-tooth wave forms todeiiection coils 16. Antenna 10 is continually rotated by means of motor22, the latter being rotatably connected to the antenna through gearreduction means 23 and shaft 24. In order to rotate the radial sweep ain synchronism with rotation of antenna 10, deflection coils 16 arerotated by motor 22, through pinion 25, and annular gear 26 mounted onthe outer periphery of the deflection coils. The arrangement is suchthat the energy emission from antenna 10 and the radial propagation ofthe electrical beam are at all times in the same direction. Wheneverradio pulses emitted from antenna 10 impinge upon remote objects, echopulses are reflected from the objects, passed to receiver 13 whereinsuch echo pulses are suitably amplified and subsequently applied tointensity control grid 21 tol a visual indication on screen 17.

In operation of the radio echo ranging apparatus disclosed in Fig. l,motor 22 continually rotates antenna 10 and deilection coils 16 insynchronism. The highly directive beam of energy from antenna 10, whichcomprises radio pulses propagating at a constant rate, is thuscontinually scanned over an area extending 360 about the antenna. Theapplication of saw-tooth varying current from generator 19 to deectioncoil 16 produces a radial sweep line a on viewing screen 17, ofoscillograph 11, which rotates in synchronism with rotation of -thedirective beam of energy emitted from the antenna. Synchronizer 20controls operation of electronic keyer 15 and saw-tooth Wave generator19 in such a manner that a radio pulse is emitted from transmitter 12simultaneously with application of every saw-tooth wave form todeflection coils 16. Whenever radio pulses emitted from the an` tennaimpinge upon remote objects, echo pulses are reected from the objects,received at antenna 10 and passed through a channel of duplexing circuit14 to a receiver 13. The echo pulses are properly amplied by receiver 13and applied to intensity control grid 21 of the oscillograph to modulatethe intensity of the electron beam thereof thus producing an indicationon oscillograph screen 17. Due to operation of synchronizer 20, suchpulse indications appear at various distances from the center of theoscillograph screen 17 in direct proportion to the range of remoteobjects, from which echo pulses are Saw-tooth wave -modulate theintensity of the electron beam to produce I l from the center of screen17 correspond to the range of remote objects with respect to theantenna. As mentioned heretofore, bias supply 19 is adjusted in such amanner to modulate the intensity of the electron beam of oscillograph 11so that sweep line a is not visible; therefore, remote objectindications b are only visible on screen 17.

As mentioned heretofore, one of the objects of the present invention isto provide novel means for facilitating the interpretation ofindications produced by radio echo ranging devices, such as a type ofapparatus disclosed in Fig. l. In Fig. 2 of the drawings, a novel deviceis disclosed for producing a series of radial Calibrating lines onscreen 17 whereby the direction of remote objects may be more readilydetermined from the indications thereof produced on the screen. Thedevice is constructed in such a manner to produce any desired number ofradial Calibrating lines on the viewing screen at any desired angularrelation therebetween. As shown, the foregoing device comprises acylindrical member 30, constructed of insulating material, mounted onshaftV 24 for synchronous rotation with antenna 10. A plurality of`metallic conductors 31 are imbedded in the outer periphery of member3i) at equally spaced intervals. As will appear more fully from thefollowing description, the number of conductors 31 determines the numberof radial calibrating lines produced on viewing screen 17, and it is tobe expressly understood that any desired number of metallic conductors31 may be employed. Metallic conductors 31 are electricallyinterconnected through circular conductor 32. The device furtherincludes stationary contact members 33 and 34 positioned 180 withrespect to each other about the periphery of member 30. The arrangementis such, upon rotation of shaft 24, that metallic conductors 31successively pass stationary contacts 33 and 34, with contact members 33and 34 simul` taneously electrically contacting a pair of metallicconductors 31. An electrical circuit is thus completed betweenstationary contact members 33 and 34, through a reflected, with respectto antenna 10. Since antenna 10 I and sweep line a rotate insynchronism, echo pulse indi'- cations of remote objects appear onoscillograph 17 at various angular positions thereon that correspond tothe angular position of remote objects from which echo pulses arereected, with respect to antenna 10.

The foregoing type of radio echo ranging apparatus thus provides avisible plan indication of the area continually scanned by the highlydirective source of energy emitted from antenna 10, which, in thepresent instant, comprises the viewing screen of the oscillograph.Indications of remote objects are produced on viewing screen 17 in sucha manner that range andvdirection, of all remote objects included withinthe field scanned by the directive beam of energy from the antenna, aresimultaneously shown. In Fig. l, indications of remote objectsdesignated by b, are shown on viewing screen 17, at various radialdistances from the center of the oscillograph screen and at differentangular positions thereon. Indications b represent positions of remoteobjects with respect to antenna 10; the angular positions of theindications, with respect to the center of viewing screen 17,

pair of metallic conductors 31 and circular conductor 32, a number oftimes for each complete revolution of shaft 24 that is equal to thenumber of metallic conductors 31. Stationary contact member 33 ismaintained at high potential from a source of high potential applied atpoint 35, through resistor 36, while stationary contact 34 is normallymaintained at ground potential through resistor 37. Condenser 38 ispositioned between stationary con tacts 33 and 34 and is charged withhigh potential from point 35 when electrical contact is not providedbetween stationary contacts 33 and 34. The low potential terminal ofcondenser 38 is connected through condenser 39 to intensity control grid21, While the low potential terminal of condenser 39 is connected toground potential through resistor 40 and condenser 41. When member 30 isin a certain angular position with respect to stationary contact members33 and 34 so that metallic conductors 31 are not in electrical contacttherewith, a high potential ,charge is applied to condenser 38 frompoint 35. When shaft 24 rotates to simultaneously move a pair ofmetallic conductors 31 into an electrical contact with stationarycontact members 33 and 34, condenser 38 is discharged, thus applying apositive pulse through condenser 39 to grid 21 of the oscillograph.Whenthe electrical connection between stationary contacts 33 and 34 isterminated, upon further rotation of shaft 24, condenser 38 is againcharged with positive potential from point 35. lt is to be expresslyunderstood, therefore, that a positive pulse is applied to grid 21whenever contact members33 and 34 simultaneously electrically contact apair of imevtallic conductors 31. The periodic application of positivepulses to intensity control grid 21 modulates the intensity of sweepline a to render the same visible at various angular positions. v

In Fig. 3'of the drawings, viewing screen 17 of oscillograph 11 isdisclosed with the radial Calibrating lines produced thereon uponoperationv of the .device disclosed, in Fig; 2.` The radial linescorrespond-to the number of metallic conductors 31 provided on member30, and are angularly positioned with respect Ato each otherin the samemanner that metallic members 31 are angularly positioned about theperiphery of member 30. It is to be expressly understood that anydesired number of radial Calibrating lines may be provided by increasingthe number of metallic conductors 31. The radial Calibrating lines shownin Fig. 3 greatly facilitate the determination of direction of remoteobjects from remote object indications b, as shown in Fig. 1. Asmentioned heretofore, the number of radial calibrated lines may beincreased to thus decrease the angular spacing therebetween to furtherfacilitate determination of. direction of remote objects with a highdegree of accuracy.

A device for producing a series of equally spaced concentric circularcalibrating lines on viewing screen 17 is disclosed in Fig. 4 of thedrawings. In this arrangement, concentric circles, corresponding topredetermined range values, are producedron viewing screen 17 in orderto facilitate determination of rangeV of remote objects. As shown, thedevice includes a highV frequency oscillator 50 which feeds to aconventional pulse generator 51- that produces positive pulses at afrequency controlled by the oscillator 5G. The positive pulses areapplied to intensity control grid 21 of oscillograph 11 to periodicallymodulate the intensity of the electron beam of the oscillograph. Theoutput of oscillator 5i) is also fed to a suitable frequency divider 52which operates to reduce the frequency of the signal to a certain ratioless than the frequency of oscillator 50. The output frequency divider52 is applied to saw-tooth wave generator 19 and electronic keyer sothat radio pulsesv are emitted from transmitter 12, and sweep line a isproduced at a frequency an integral number of times less than thefrequency of loscillator 5t) determinedfby frequency divider 52. Also,since the positive pulses from generator 51 applied to intensity controlgrid 21 are at a frequency equal to the frequency of oscillator 50, thepositiveapulses are applied to grid 21 at a rate a similar number oftimes greater than the rate of generation of sweep a.

Operation of the foregoing` device-may be more readily understood withreference to Fig. 5 which discloses propagation of sweep line a. Sincethe output of frequency divider 52 initiates propagation of sweep line aand simultaneously triggers transmitter 12, an indication of thetransmitted pulse is produced on the sweep line at substantially thesame instant the latter originates, as shown in the figure. Since pulsegenerator 51 is operating at a frequency a number of times greater thanthe frequency of the output of frequency divider 52 an equal number ofpositive pulses are applied to grid 21 during propagation of each sweepline a. Such pulses are produced on the sweep line at equal intervals asshown by pulse indication c in Fig. 5. In the instant arrangement,positive pulses are applied to grid 21 at a rate ve times greater thanthe rate of propagation of sweep a. The distance between each pulseindication c on the sweep line is thus equal to one fifth therangerwhich the sweep line is calibrated. in Fig. 6 of the drawingstheviewing screen 17 of oscillograph 11 is disclosed with a series ofequally spaced concentric circular Calibrating marks thereon which areproduced upon operation of the device disclosed in Fig. 4, when motor 22is rotating at a sufcient speed to produce persistent indications onscreen 17 When motor 22 is operating at a lower rate of speed, theconcentric circular Calibrating marks appear visible over a certain arcwhich moves in synchronism with rotation of the antenna. Fig. 6 also`discloses the visible radial Calibrating lines shown in. Fig. 3 inorder to illustrate the simultaneous utilization of radial Calibratinglines and concentric Calibrating circles for simultaneously facilitatingdetermination `of range and direction of remote obf Y There is thusprovided by the Ypresent invention novel means for facilitating theinterpretation of indications produced by radio echo ranging devices orsimilar apparatuscs of the type describedA herein. Such means producesvisual radial marks on the viewing screen of the apparatus which arecalibrated as a function of direction, as well asproducing a series ofvisual concentric circular marks on the viewing screen which arecalibrated as a function ofrange. The radial or circular Calibratingmarks are produced in such a manner that the same may bel individuallyor simultaneously produced on the indicator and the same function togreatly assist in determination of rangetand direction of remote objectsfrom indications thereofproduced on theindicator.

Although several embodiments of the present invention have beendisclosed and described herein, it is to be expressly understood thatvarious changes and substitutions may be made therein without departingfrom the spirit of the invention as well understood by those skilled inthe art. Reference therefore will be had to the appended claims foradefinition of the limits of the invention.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What is claimed is:

1. An apparatus for indicating positions of remote objects comprisingmeans producing a directional energy emission, means rotating saiddirectional energy emission for continually scanning an area about theapparatus, means receiving energy reflections whenever said directionalenergy emission impinges upon and reects from a remote object includedwithin said scanned area, means producing a visual plan representationof said scanned area, means responsive to reception of said reflectedenergy for producing visual indication on said plan rep resentation ofeach remote object included in said area at a linear position and at anangular position with respect to a reference direction of saidrepresentation respectively in accordance with range and direction ofeach remote object with respect to the apparatus, and means producingradial Calibrating marks on said representation for facilitatingdetermination of directions of remote objects from said indications. Y

2. An apparatus for indicating positions of remote objects comprisingmeans producing a directional energy emission, means rotating saiddirectional energy emission for continually scanning an area about theapparatus, means receiving energy reflections Whenever said directionalenergy emission impinges upon and reflects from a remote object includedwithin said scanned area, means producing a visual plan representationof said scanned area, means responsive to reception of said reiectedenergy for producing visual indication on said plan representation ofeach remote object included in said area at a radial distance and at anangular position with respect to a reference point on saidrepresentation respectively in accordance with range and direction ofeach remote object with respect to the apparatus, and means producingcalibrated concentric circular marks on said representation forfacilitating determination of range of remote objects from saidindications` 3. An apparatus for indicating positions of remote objectscomprising means producing a directional energy emission, means rotatingsaid'directional energy emission for continually scanning an area aboutthe apparatus, means receiving energy reections whenever saiddirectional energy ernissionvimpinges upon and reects from a remoteobject included Within said'scanned area, means producing a visual planrepresentation of said scanned area, means responsive to reception ofsaid reected energy for producing visual indication on said plan`representation of each remote object included in said area at a radialdistance and at an angular position with respect to a reference point onsaid representation respectively in accordance with range and directionof each remote object with respect to the apparatus, means producingradial Calibrating marks on said representation for facilitatingdetermination of remote objects, and means producing concentric circularmarks on said representation for facilitating determination of range ofremote objects. 4. An apparatus for indicating positions of remoteobjects in space comprising a directional beam antenna, means applying asource of energy to said antenna for producing a highly directive energyemission therefrom, means continually rotating said antenna forcontinually scanning an area about said apparatus with said directiveenergy, means receiving energy reflections whenever said directiveenergy impinges upon and reliects from remote objects included Withinsaid scanned area, a cathode ray indicator, means continually deftectingthe electron beam of said indicator whereby said beam continuallyradially scans the viewing screen of said indicator in a directioncorresponding to the direction of said directive energy emission, meansmodulating the intensity of said electron beam in accordance with thereception of said energy reflections for producing visual indications onsaid screen of remote objects included within said area, with theindications having certain radial distances lat certain angularpositions with respect to the center of said screen respectively inaccordance with the range and direction of each remote object withrespect to said antenna, and means producing radial calibrating marks onsaid screen for facilitating determination of direction of remoteobjects. 5. An apparatus for indicating positions of remote ob jects inspace comprising a directional beam antenna, means applying a source ofenergy to said antenna for producing a highly directive energy emissiontherefrom,

means continually rotating said -antenna for continually scanning anarea about said apparatus with said directive energy, means receivingenergy reflections whenever said directive energy impinges upon andreflects from remote objects included within said scanned area, acathode ray indicator, means continually deecting the electron beam ofsaid indicator whereby said beam continually radially scans the viewingscreen of said indicator in a direction corresponding to the directionof said directive energy emission, means modulating the intensity ofSaid electron beam in accordance with the reception of said energyreflections for producing visual indications on said screen of remoteobjects included within said area, with the indications having certainradial distances at certain angular positions with respect to the centerof said screen respectively in accordance with the range and directionof each remote object with respect to said antenna, and means producingcalibrated concentric circular marks on said screen for facilitatingdetermination of range of remote objects.

6. An apparatus for indicating positions of remote objects in spacecomprising a directional beam antenna, means applying a source of energyto said antenna for producing a highly directive energy emissiontherefrom, means continually rotating said antenna for continuallyscanning an area about said apparatus with said directive energy, meansreceiving energy reflections whenever said directive energy impingesupon and reflects from remote objects included within said scanned area,a cathode ray indicator, means continually deecting the electron beam ofsaid indicator whereby said beam continually radially scans the viewingscreen of said indicator in a direction corresponding to the directionof said directive energy emission, means modulating the intensity ofsaid electron beam in accordance with the reception of said energyreflections for producing visual indications on said screen of remoteobjects included within said area, with the indications having certainradial distances at certain angular positions with respect Vto thecenter of said screen respec- 8 v t tively in accordance with the rangeand direction of each remote object with respect to said antenna, meansproducing radial calibrating marks on said screen for facilitatingdetermination of direction of remote objects, and means producingconcentric `Calibrating circular marks on said screen for facilitatingdetermination of range of remote objects.

7. An apparatus for indicating positions of remote objects in spacecomprising a directional beam antenna, means applying a source of energyto said antenna for producing a highly directive energy emissiontherefrom, means continually rotating said antenna for continuallyscanning an area about said apparatus with said directive energy, meansreceiving energy reflections whenever said directive energy impingesupon and reflects from remote objects included within said scanned area,a cathode ray indicator, means continually deflecting the electron beamof said indicator whereby said beam continually radially scans theviewing screen of said indicator in a direction corresponding to thedirection of said directive energy emission, means modulating theintensity of said electron 4beam in accordance with the reception ofsaid energy reflections for producing visual indications on said screenof remo-te objects included within said area, with the indicationshaving certain radial distances at certain angular positions withrespect to the center of said screen respectively in accordance with therange and direction of each remote object with respect to said antenna,and means rotating in synchronism with said antenna for modulating theintensity of said electron beam during radial scanning thereof atcertain angular positions during rotation thereof for producing radialdirection `Calibrating marks on said screen.

8. An apparatus for indicating positions of remote objects in spacecomprising a directional beam antenna, means applying a sourceV ofenergy to said antenna for producing a highly directive energy emissiontherefrom, means continually rotating said antenna for continuallyscanning an area about said apparatus with said directive energy, meansreceiving energy retiections whenever said directive energy impingesupon and reflects from remote objects included with said scanned area, acathode ray indicator, means continually deecting the electron beam ofsaid indicator whereby said beam continually radially scans the viewingscreen of said indicator in a direction corresponding to the directionof said directive energy emission, means modulating the intensity ofsaid electron beam in accordance with the reception of said energyreflections for producing visual indications on said screen of remoteobjects included within said area, with the indications having certainradial distances at certain angular positions with respect to the centerof said screen respectively in accordance with the range and directionof each remote object with respect to said antenna, means responsive torotation of said antenna for modulating the intensity of said electronbeam during radial scanning thereof when the antenna occupies certainangular positions during rotation thereof whereby radial directionCalibrating marks are produced on said screen.

9. An apparatus for indicating positions of remote objects in spacecomprising a directional beam antenna, means-applying a source of energyto said antenna for producing a highly directive energy emissiontherefrom, means continually rotating said antenna for continuallyscanning an area about said apparatus with said directive energy, meansreceiving energy reflections whenever said directive energy impingesupon and reects from remote objects included within said scanned area, acathode ray indicator, means continually deflecting the electron beam ofsaid indicator whereby said beam continually radially scans the viewingscreen of said indicator in a direction corresponding to the directionof said directive energy emission, means modulating the intensity ofsaid electron beam in accordance with the reception of said energyreflections for producing .visual indications on said screen of remoteobjects included within said area, with the indications having certainradialdistances at certain angular positions with respect to the centerof said screen respectively in accordance with the range and directionof each remote object with respect to said antenna, and meansintermittently modulating the intensity of said electron beam at equallyspaced time intervals during radial scanning thereof for producingconcentric circular range Calibrating marks on said screen.

10. An apparatus for indicating positions of remote objects in spacecomprising a directional beam antenna, means applying a source of energyto said antenna for producing a highly directive energy emissiontherefrom, means continually rotating said. antenna for continuallyscanning an area about said4 apparatus with said directive energy, meansreceiving energy reflections whenever said directive energy impingesupon and reflects from remote objects included within said scanned area,a cathode ray indicator, means continually deecting the electron beam ofsaid indicator whereby said beam continually radially scans the viewingscreenV of said indicator in a direction corresponding to the directionof said directive lenergy emission, means modulating the intensity ofsaid electron beam in accordance with the reception of said energyrellections for producing visual indications on said screen of remoteobjects included within said area, with the indications having certainradial distances at certain angular positionswith respect to the centerof said screen respectively in accordance with the range and directionof each remote object with respect to said antenna, means responsive torotation of said antenna for modulating the intensity of said electronmeans during radial scanning thereof when the antenna occupies certainangular positions during rotation thereof whereby radialdirectioncalibratingmarks are produced on said screen, and means intermittentlymodulating the electron beam at equally spaced time intervals duringeach radial scanning thereof for producing concentric circular rangeCalibrating marks on said screen.

11. An apparatus for indicating positions of remote objects in spacecomprising a directional beam antenna, means applying a source of energyto said antenna for producing a highly directive energy emissiontherefrom, means continually rotating said antenna for continuallyscanning an area about said apparatus with said directive energy, meansreceiving energy reflections whenever said directive energy impingesupon and reflects from remote objects included within said scanned area,a cathode ray indicator, means continually dellecting the electron beamof said indicator whereby said beam continually radially scans theviewing screen of said indicator in a direction corresponding to thedirection of said directive energy emission, means modulating theintensity of said electron beam in accordance with the reception of saidenergy reections for producing visual indications on said screen ofremote objects included within said area, with the indications havingcertain radial distances at certain angular positions with respect tothe center of said screen respectively in accordance with the range anddirection of each remote object with respect to said antenna, meansgenerating a plurality of impulses at equally spaced intervals duringeach complete rotation of said antenna, and means applying said impulsesto said indicator for modulating the intensity of said electron beamwhereby equally spaced radial calibrating marks are produced on saidscreen.

12. An apparatus for indicating positions of remote objects in spacecomprising a directional beam antenna, means applying a source of energyto said antenna for producing a highly directive energy emissiontherefrom, means continually rotating said antenna for continuallyscanning an area about said apparatus with said directive energy, meansreceiving energy rellections whenever said directive energy impingesupon and reflects from remote objects included within said scanned area,a cathode ray indicator, means continually deecting the electron beam ofsaid indicator whereby ,said` beam continually radially scans theviewing screen of said indicator in a direction corresponding to thedirection of said directive energy emission, means modulating thevintensity oftsaid electron beam in accordance with the reception ofsaid energy reflections for producing visual indications on said screenof remote objects included within said area, with the indications havingcertain radial distances at certain angular positions with respect tothecenter of said screen respectively in accordance with the range anddirection of each remote object with respect to said antenna, acondenser, means continually supplying a source of potential to saidcondenser,rmeans discharging said condenser at equally spaced intervalsduring each complete rotation of said antenna for producing equallyspaced impulses, and means applying said impulses to said indicator formodulating the intensity of said electron beam whereby equally spacedradial calibration marks areproduced on said screen.

13. An apparatus for indicating positions of remote objects in spacecomprising a directional beam antenna, means applying a source of energyto said antenna for producing a highly directive energy emissiontherefrom, means continually rotating said antenna for continuallyscanning an area about said apparatus with said directive energy, meansreceiving energy reflections whenever said directive energy impingesupon and reects from remote objects included within said scanned area,an indicator including means generating an electron beam, meanscontinuallydeilecting the said electron beam whereby said beamcontinually radially scans the viewing screen of said indicator insynchronism with the rate of propagation of said directive energyemission in a direction corresponding to the direction of said directiveenergy emission, means modulating the intensity of said electron beam inaccordance with the reception of said energy reflections for pro ducingvisual indications on said screen of remote objects included within saidarea, with the indications having certain radial distances at certainangular positions with respect to the center of said screen respectivelyin accordance with the range and direction of each remote object withrespect to said antenna, means producing impulses at a rate greater thanthe rate of generation of said directive energy emission, means applyingsaid impulses to said indicator for intermittently modulating theintensity of said electron beam at equally spaced time intervals duringeach radial scanning thereof whereby a series of equally spacedconcentric circular Calibrating marks are produced on said screen uponcomplete rotation of said antenna.

14. In a radio apparatus for object locating, means for comparing thedirection of an object to a reference direction comprising, a generatorof ultra high frequency energy pulses, means for radiating the pulses ina directive electromagnetic beam, means for periodically scanning afield of view including the object with the beam, means for generating adirectional sweep voltage dependent upon the instantaneous direction ofthe beam, means for receiving energy reflected from the object,indicator means for representing the reected energy by a luminous image,means actuated by the directional sweep voltage for positioning theindicator image according to the direction of the beam when the objectis scanned, and electronic means for producing a directional referenceline on said indicator.

l5. In a radio apparatus for object locating, means for comparing thedirection of an object to a reference direction comprising, a generatorof ultra high frequency energy pulses, means for radiating the pulses ina directive electromagnetic beam, means for periodically scanning a eldincluding the object with the beam, means for generating a directionalsweep voltage dependent upon the instantaneous direction of the beam,means for receiving energy reected from the object, indicator means forrepresenting the retlected energy by a luminous image, means actuated bythe directional sweep voltage for positioning the indicator imageaccording to the direction of the beam when the object is scanned, andmeans for producing a directional index on said indicator at a positioncorresponding to zero directional sweep voltage.

16. 1n a radio apparatus for object locating, means for comparing thedirection of an object to a reference direction comprising a generatorof ultra high frequency energy pulses, means for radiating the pulses,means for radiating the pulses in a directive electromagetic beam, meansfor periodically scanning a iield of view including the lobject with thebeam, means for generating a directional sweep voltage dependent uponthe instantaneous direction .of the beam, means for receiving energy'reilected from the object, indicator means for representing the reectedenergy by an image, means actuated by the directional sweep voltage forpositioning the indicator image according to direction of the beam whenthe object is I scanned, and means coordinated with said scanning meansfor periodically producing on said indicator at a position correspondingto a predetermined directional sweep voltage, an image representing thereference direction of said electromagnetic beam.

17. I n a radio apparatus for object locating, means for comparing thedirection of an object to a reference direction comprising, a generatorof ultra high frequency energy pulses, means for radiating the pulses ina directive electromagnetic beam, means for periodically scanning afield of view including the object with the beam, means for generating adirectional deflecting eld dependent upon the instantaneous direction ofthe beam, means for 'receiving energy reflected from the object,indicator means for representing the reiiected energy by a luminousimage, means actuated by the directional deecting field for positioningthe ind-icator image according to the direction of the beam when theobject is scanned, and electronic means for producing a directionalreference line on said indicator.

18. In a radio apparatus for object locating, means for comparing thedirection of an object to a reference direction comprising, a generatorof ultra high frequency energy pulses, means for radiating the pulses ina directive electromagnetic beam, means for periodically scanning aeldof view including the lobject with the beam, means for generating asweep voltage, means for receiving energy reflected from the object,indicator means for representing the reected energy by a luminous image,means utilizing the sweep voltage for positioning the indicator imageaccording to the direction of the beam when the object is scanned, andelectronic means for producing a directional reference line on saidindicator.

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